Method and Apparatus for Insulating Panels

ABSTRACT

An insulation structure attached to a wall having a multitude of anchors projecting from the wall to support the insulation structure includes a permanent refractory layer adjacent the wall and a restorable refractory layer adjacent the permanent refractory layer. An anchor supports the refractory material and includes a first stud and a second stud. The second stud includes a cap connected to a shaft, wherein the cap defines an indentation on a side of the cap opposite the shaft. The second stud receives the first stud within the indentation within the cap. The double layer of refractory material allows for maintenance and replacement of a restorable refractory layer without disturbing or replacing the permanent refractory layer.

FIELD OF THE INVENTION

The invention relates to insulating water cooled panels exposed to hightemperatures and/or other adverse conditions with a double layer ofrefractory material.

BACKGROUND

Numerous kinds of enclosures have internal surfaces that surroundadverse atmospheric conditions therein, such as high temperatures,frequently oscillating temperatures, flue gases carrying abrasiveparticulates at high speeds, corrosive fluids, and the like. One exampleis a furnace used in the steel industry for smelting iron ore and otheriron yielding constituents (e.g., scrap iron and pig iron) to produceslag and molten iron. Temperatures in the furnace reach or even exceed1600 degrees Centigrade at the peak of the chemical reactions. Withmolten iron and molten slag inside the furnace, the interior walls ofthe furnace face extraordinarily harsh conditions.

One measure used to preserve the structural integrity of the furnacewalls is to install water-cooled panels between the wall structures andthe furnace interior. The water cooled panels include tubes or pipeswith water running therein to extend their usability. The water cooledpanels, however, face the above-noted extreme conditions within thefurnace and likewise need structural protection. One present way ofprotecting water cooled panels includes insulating the panels withrefractory bricks or tiles hanging from studs projecting from thepanels. Other systems include applying pegs and mechanical parts tointerior furnace walls to enhance the ability of slag to cling to thewater cooled panels and form an insulating layer. Even more modernapproaches to insulating furnaces include lining the interior of thefurnace with a layer of refractory material that is structurally andcompositionally rugged such that the layer withstands the temperatures,chemical reactions, and physical abrasions that are inherent in thefurnace environments. Single layers of refractory materials are appliedto an interior wall (e.g., over cooling tube panels) and supported bythe above noted pegs or other mechanical structures to maintain it inplace. The pegs or studs are often projections emanating from the tubes,and the refractory material is applied directly onto and between thetubes by hammering, pouring, spraying, dipping or otherwise coveringspaces between and over the studs providing support.

The above noted tiles, bricks, and applied insulating layer bring forthcomplications, however. Tiles and bricks have spaces between them andpotential discontinuities that affect structural integrity. A layer ofrefractory material wears away, exposing the supporting materialthereunder. Once the tube material is exposed, its usability becomesfairly limited. Exposing a single layer of refractory material to theconditions within a furnace yields limits the usability of the protectedmaterial as the layer itself loses its stability in case of liningfailure.

BRIEF SUMMARY

In a first embodiment, an insulation structure that is attached to awall with a multitude of anchors projecting from the wall includes apermanent refractory layer adjacent to the wall and a restorablerefractory layer adjacent the permanent refractory layer.

In another embodiment, a method of insulating a wall exposed tocorrosive conditions includes applying a permanent refractory layer ontothe wall and applying a restorable refractory layer onto the permanentrefractory layer, wherein an outer surface of the restorable refractorylayer is exposed to corrosive conditions.

A third embodiment of the disclosed method entails insulating a wallexposed to adverse conditions and includes the steps of (i) attaching afirst stud to the wall; (ii) attaching a second stud, having a cap and ashaft, to the first stud such that the cap of the second stud is betweenthe first stud and the shaft of said second stud, (iii) applying apermanent refractory layer to the wall, wherein the permanent refractorylayer covers at least a portion of the first stud and at least a portionof the cap of the second stud; and (iv) applying a restorable refractorylayer to the permanent refractory layer.

A fourth embodiment provides an anchor for supporting refractorymaterial insulating a wall, and the anchor includes a first stud, asecond stud having a cap connected to a shaft, wherein the cap definesan indentation on a side of the cap opposite the shaft. The second studreceives the first stud within the indentation within the cap.

In yet another embodiment, an anchor is for supporting refractorymaterial insulating a wall, and the anchor includes a cap having a studextending from one side of the cap and a shaft extending from anopposite side of the cap.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is a prior art illustration of a water cooled panel on whichrefractory materials used herein may be applied.

FIG. 1B is a prior art illustration of a series of water or coolanttubes on the panel of FIG. 1A.

FIG. 2 is a plan view of a coolant tube that may be a portion of a watercooled panel and shows a double refractory layer and supporting anchorsas disclosed herein.

FIG. 3A is a plan view of a first stud that may be a part of amulti-piece anchor as disclosed herein.

FIG. 3B is a plan view of a second stud that may be a part of amulti-piece anchor as disclosed herein.

FIG. 4 is a plan view of a wall or surface on which a straight firststud has been attached as part of a multi-piece anchor installation.

FIG. 5 is a plan view of a wall or surface on which an entire anchor hasbeen installed to support refractory materials as disclosed herein.

DETAILED DESCRIPTION

The interior walls of furnaces or other enclosures often surroundadverse or corrosive conditions such as high temperatures, frequenttemperature oscillations, flue gases containing abrasive particulates,corrosive fluids, and the like. Terms such as “adverse conditions” and“corrosive conditions” are used to convey any conditions within anenclosure that will stress the walls or panels of a structure. The termsare used in their broadest sense and do not limit the apparatus ormethods described herein. Structures that house these kinds ofindustrial environments must be able to withstand the chemicalreactions, physical stress, and operating conditions present therein,and Reference Number (60) in the Figures of this disclosure is a generalindication showing these kinds of adverse conditions without limitingthe invention disclosed herein.

The structures incorporating the refractory layers disclosed herein mayincorporate protective features such as water-cooled panels that coolthe walls of the structure and inevitably face intensely adverseconditions. The phrase “water cooled panel” and similar descriptors arenot limiting of the invention disclosed herein, as the disclosure belowapplies equally to coolants other than water and structures other thanpanels.

The water cooled panels (20) of FIG. 1A often utilize water conduits(25), such as tubes or pipe structures, allowing water or other coolantsto flow there through, absorbing some of the heat energy that wouldotherwise deteriorate the walls of the enclosure (e.g., water cooledpanels lining the walls of a furnace). As shown in FIG. 1A, the tubularmembers (25) of a water cooled panel include pegs or studs (30)extending substantially perpendicularly from the outer surface of thetubes (25). As noted above, these studs (30) may allow refractory tilesto hang over the water cooled panel, or the studs may provide an anchorpoint for slag in a steel furnace to accumulate along the wall of thefurnace, thereby forming a layer of insulation protecting the panel.FIG. 1B shows a close up view of the cooling tubes associated with awater cooled panel and the studs (30) extending from each tube. Thearrangements shown in FIGS. 1A and 1B may also be conducive to applyinga single layer of refractory material to the water cooled panel suchthat the single layer refractory covers the tubes (25) and at leastportions of the studs (30).

In one embodiment of the wall insulation method described herein andshown in FIG. 2, two layers of refractory are applied to a wall in afurnace or similar enclosure. The two layers of refractory may also beapplied over water cooled panels and associated tubular members (25),similar to the structure shown in FIG. 1A. The double layer refractoryincludes a permanent refractory layer (40) and a restorable refractorylayer (50) adjacent the permanent refractory layer. In anotherembodiment, the restorable refractory layer (50) comprises a first side(52) and a second side (53). The first side (52) is an exposed surfacesubject to adverse conditions (60) that wear down the exposed surface.Similarly, the permanent refractory layer (40) has a first permanentlayer surface (42) and a second permanent layer surface (43). In oneembodiment, shown in FIG. 2, the second side (53) of the restorablerefractory layer (50) is adjacent, or even directly adjacent, the firstpermanent layer surface (42) of the permanent layer (40). The secondpermanent layer surface (43) of the permanent layer (40) is adjacent, oreven directly adjacent, the wall, panel or as shown in FIG. 2, thetubular member (25) of a water cooled panel (20).

The double refractory layer (40, 50) protects a wall in a furnace orother enclosure in a manner that allows maintenance on the installationto be extremely convenient. By incorporating a restorable refractorylayer (50) over a permanent refractory layer (40), the adverseconditions (60) within the enclosure, including high and fluctuatingtemperatures, flue gases with abrasive particulates, corrosive fluids,chemical reactions, and other harsh or corrosive parameters affect onlythe restorable refractory layer (40) before the wall or panel is removedfor maintenance. The method of applying a permanent refractory layer(40) and a restorable refractory layer (50) provides an avenue forinspecting the insulating refractory (40, 50) when the restorablerefractory layer (50) wears down to a predetermined thickness. As shownin FIG. 2, the restorable refractory layer (50) is applied atop thepermanent refractory layer (40) and covers the supporting anchors (105).As the adverse conditions (60) within the enclosure wear down therestorable refractory layer (50), the tips (107) of the anchors (105)are exposed. Eventually, the restorable refractory layer (50) is exposedto a point at which the cap (90) is exposed. Without limiting theinvention to any one embodiment, the wear on the restorable refractorylayer (50) may remove the refractory material all the way down to thecap (90), which is an effective limit for signaling time to provide atotally safe restoration. The adverse conditions (60) also wear down theanchors (105), which can require replacement as well. In the embodimentshown in FIG. 2, a tubular member (25) of a water cooled panel utilizesthe double refractory layer (40, 50) to protect the water cooled panel.When the restorable refractory layer (50) wears down or corrodes to apredetermined thickness or when the caps (90) show through therefractory layer and begin to show wear as well, the entire panel orwall section may be removed for maintenance.

The maintenance of a wall section or water cooled panel (20) asdisclosed herein is significantly more expedient than prior forms ofinsulated walls. By insulating the wall or panel in a double refractoryconfiguration, the corrosive conditions within the enclosure do notsignificantly affect the permanent refractory layer (40) installeddirectly adjacent the wall or panel structure. The wall or panel (25)may be removed from a furnace or other installation for repair prior tolosing the entire depth of the insulating refractory (40, 50). Applyinga new restorable refractory layer (50) over the original permanentrefractory layer (40) is a much simpler process than building anentirely new panel with a new single layer refractory or even patching asingle layer refractory.

In order to accomplish the insulation method described above, thepermanent refractory layer (40) and the restorable refractory layer (50)may be made of different compositions. The refractory compositions mayinclude, but are not limited to, carbon graphite, silicon carbide,mixtures of magnesium and silicon carbide, magnesium oxide, aluminumoxide, silicon dioxide, zirconium dioxide, titanium dioxide, chromiumoxide, and alloys thereof. The selection of compositions for eachrefractory layer may depend upon the adverse conditions affecting therestorable refractory layer and the cost of replacing the respectiverefractory layers.

Utilizing a double refractory embodiment as shown in FIG. 2 may beimplemented using an anchor (105). Without limiting the invention, inone embodiment, a plurality of anchors (105) extend across a furnacewall or across the tubes (25) of a water cooled panel. The anchors (105)support the refractory material (40, 50) which is applied between,around, and over the anchors (105) by methods including, but not limitedto, hammering, pouring, spraying, dipping, and the like.

In one embodiment that does not limit the invention disclosed herein,the anchors (105) may include either a one piece or multi-part design,whichever is more convenient for the installation at hand. For instance,when the space between two consecutive studs does not allow theapplication of a single piece stud that contains the two sections in oneintegrated piece, then a multi-piece installation is appropriate.Ultimately, in one non-limiting embodiment of the anchor (105) shown inFIG. 2, the anchor (105) includes a cap (90) that extends substantiallyhorizontally and divides a straight section or sections (75, 95) of theanchor (105). The cap (90) adds additional surface area for stabilizingthe application of both the permanent refractory layer (40) and therestorable refractory layer (50). As shown in FIG. 2, the caps (90)provide a bracing structure holding the permanent refractory layer (40)below the cap and supporting the restorable refractory layer (50)extending from the permanent refractory layer.

A method of insulating a wall exposed to adverse or corrosive conditionsmay include installing the anchor (105) on a water cooled panel (i.e.,on the tubes or piping system of the panel) or on a wall of anenclosure. In one embodiment, the anchor (105) is a single piecepre-fabricated device with at least one straight section or straightsections (75, 95) extending from opposite portions of a cap portion(90).

In another embodiment that does not limit the scope of the apparatusesand methods disclosed herein, the anchor (105) has a multi-partconstruction that is assembled as part of an installation process forinsulating a wall or panel with refractory material. The multi-partassembly of an anchor (105) may include a first straight section, orfirst stud (75), shown in FIG. 3A, that is attachable to a wall ortubular system of a water cooled panel (20), and particularly attachablealong the tubes (25). The stud (75) has a first end (77A) and a secondend (77B). As shown in FIG. 3A without limiting the invention, the stud(75) may include a threaded, notched, ribbed or knurled surface thatallows the refractory material used in insulating the wall to adhere tothe stud (75) for support. The multi-piece construction alsoincorporates a second stud (80) as shown in FIG. 3B. The second stud(80) has a shaft (95) with a first shaft end (81A) and a second shaftend (81B). The second shaft end (81B) connects a cap (90), which mayresult in the second stud (80) having a general “mushroom” shape, or inother words, the second stud (80) has a straight portion in the shaft(95) and a transverse portion (90) that forms a substantially horizontalcap over the shaft (95). The cap (90) defines an indentation (93) on aside of the cap (90) opposite the shaft (95). The second stud (80),therefore, is configured to receive the first stud (75) within theindentation (93) within the cap (90).

The multi-piece configuration of an anchor for the refractoryinsulations presents a way of attaching a first end (77A) of a firststud (75) to a wall or water cooled panel (20) by a first weld (71A).See FIG. 3. The second end (77B) of the first stud (75) connects by asecond weld (71B) within the indentation (93) defined by the cap (90) ofthe second stud (80). The overall anchor (105) is shown in FIG. 5 in thecontext of welding the anchor (115) to a tube (25) within a water cooledpanel (20).

FIG. 5 illustrates that a refractory layer anchor (105) may incorporatea single-piece fabrication shaped to include generally straight sections(75, 95) extending from opposite sides of a cap (90). The single piece,therefore, would be attached to the wall or panel by a weld (71A) orotherwise connected to the panel at one end (77A). The same generalshape for the anchor (105) may be accomplished by attaching amulti-piece embodiment according to the description above. The result isan anchor attached to a wall or panel in a corrosive environment andconfigured to support a refractory insulation. The anchor includes a capportion that engages two different layers of refractory material, onepermanent layer (40) of refractory material extending from the panel(20) or tube (25) toward the midsection of the cap (90) and anotherlayer (50) extending from the permanent layer (50) and having an exposedtip (107). The straight sections (i.e., the stud (75) and the shaft(95)) may have an exterior (72) that is not entirely smooth (e.g.,etched, knurled, or threaded).

One method of accomplishing a double refractory layer (40, 50) as shownin FIG. 2 includes attaching a first stud (75) to a wall or watercooling tube (25) within an enclosure that surrounds adverse orcorrosive conditions. The first stud may be attached by a stud weldingprocess or by any convenient means that is sufficient to affix the firststud (75) to the wall securely and provide total metal contact betweenthe stud and the tube. A second stud (80) is attached to the first stud(75), and in one embodiment, the second stud (80) has a cap (90) and ashaft. The second stud (80) is attached to the first stud (75) such thatthe cap (90) of the second stud (80) is between the first stud (75) andthe shaft (95) of the second stud (80). Overall, the first stud (75),the second stud (80), and the intermediate cap (90) between the two areattached to the interior wall or water cooled panel to supportrefractory layers (40, 50) described herein. Accordingly, in the methodof this disclosure, a permanent refractory layer (40) is applied to thewall and covers at least a portion of the first stud (75) and at least aportion of the cap (90) of the second stud (80). The method continueswith applying a restorable refractory layer (50) to the permanentrefractory layer (40). The restorable refractory extends from about themidsection of the cap (90) within the anchor (105). The restorablerefractory layer (50) may be flush with the tips (107) of the anchors(105) or may entirely cover the portion of the anchor (105) extendingoutwardly from the cap (90). In another embodiment, the restorablerefractory layer (50) may exceed the length of the anchor (105) by adimension that is between about ⅛ of an inch and ½ of an inch. When thedepth of the restorable refractory layer (50) extends too far above thelength of the anchor (105), then the extended portion of the restorablerefractory layer (50) above the anchor (105) cannot benefit from acooling effect provided by the anchor (105). Without a cooling effectfrom the anchor (105), the restorable refractory layer (50) extendingover the anchor (105) will collapse.

The wall to which the refractory layers are applied may be a removablepanel of cooling tubes or an entire component such as a water cooledduct, an elbow, etc., and the step of attaching the first stud (75)includes attaching at least one straight stud (75) to at least one ofthe cooling tubes (25) in a position that is substantially perpendicularto the cooling tube. The second stud (80) is attached to the first stud(75), and the two studs support at least two refractory layers (40, 50)insulating the wall installed in a corrosive environment. The tworefractory layers (40, 50) include at least one permanent layer (40) ofrefractory material and at least one restorable layer (50) of refractorymaterial. The restorable layer (50) of refractory material is exposed toconditions (60) within the enclosure that wear the restorable layer downto thicknesses that expose the anchors. Of course, exposed anchors (105)also wear down and may need to be replaced as well. The method ofinsulating a wall herein places a restorable layer of refractorymaterial (50) in an outward position within an enclosure, such that therestorable layer of refractory material (50) is subject to corrosiveconditions (60) within the subject enclosure. By providing a means forreplenishing the restorable layer (50) without disturbing the permanentlayer (40) thereunder, the permanent layer (40) may last significantlylonger as does the metal wall structure protected by the double layersystem. In embodiments utilizing a two piece anchor, a worn restorablelayer may allow access to the second stud (80), which can be removedfrom the first stud (75) and replaced with a new second stud (80).Accordingly, the insulation structure and associated anchor set forthherein allows for repair of portions of the insulation or anchorsaccording to need. Insulated installations within the ambit of thismethod will not require an entire re-manufacturing of the wholerefractory insulation during maintenance. The maintenance of therefractory installation is therefore significantly more economical.

While specific embodiments of the invention have been illustrated anddescribed herein, it is realized that numerous modifications and changeswill occur to those skilled in the art. It is therefore to be understoodthat the appended claims are intended to cover all such modificationsand changes as fall within the true spirit and scope of the invention.

1. An insulation structure attached to a wall, the insulation structurecomprising: a multitude of anchors projecting from the wall andsupporting the insulation structure; a permanent refractory layeradjacent the wall; and a restorable refractory layer adjacent saidpermanent refractory layer, wherein the anchors have respective capsabout midway along the length of the anchors, and said permanentrefractory layer extends to about the midsection of the caps.
 2. Aninsulation structure according to claim 1, wherein a side of saidrestorable refractory layer, opposite said permanent refractory layer,is an exposed surface.
 3. An insulation structure according to claim 1,wherein said permanent refractory layer and said restorable refractorylayer comprise different compositions.
 4. An insulation structureaccording to claim 3, wherein said compositions are selected from thegroup consisting of carbon graphite, silicon carbide, mixtures ofmagnesium and silicon carbide, magnesium oxide, aluminum oxide, silicondioxide, zirconium dioxide, titanium dioxide, chromium oxide, and alloysthereof.
 5. An insulation structure according to claim 1, wherein saidpermanent refractory layer extends from the wall to a midsection of therespective anchors, and said restorable refractory layer extends fromsaid permanent refractory layer.
 6. (canceled)
 7. An insulationstructure according to claim 1, wherein said restorable refractory layerextends from said permanent refractory layer and covers the entirety ofthe anchors.
 8. An insulation structure according, to claim 1, whereinthe wall is a removable panel of cooling tubes having a plurality ofanchors extending substantially perpendicularly from the tubes, andwherein said permanent layer of refractory material covers at least aportion of the tubes.
 9. A method of insulating a wall exposed tocorrosive conditions, the method comprising: applying a permanentrefractory layer directly onto the wall; and applying, a restorablerefractory layer directly onto said permanent refractory layer, whereinan outer surface of said restorable refractory layer is exposed to thecorrosive conditions.
 10. A method of insulating a wall exposed toadverse conditions, the method comprising: attaching, a first stud tothe wall; attaching a second stud having a cap and a shaft to said firststud such that the cap of the second stud is between the first stud andthe shaft of said second stud; and after attaching said second stud tosaid first stud, applying a permanent refractory layer directly to thewall, said permanent refractory layer covering at least a portion of thefirst stud and at least a portion of the cap of the second stud; andapplying a restorable refractory layer directly to the permanentrefractory layer.
 11. A method of insulating a wall according to claim10, further comprising the step of covering the entirety of the secondstud with the restorable refractory layer.
 12. A method of insulating awall according to claim 11, wherein the wall is a removable panel ofcooling tubes, and the step of attaching the first stud comprisesattaching at least one straight stud to at least one of the coolingtubes in a position that is substantially perpendicular to the coolingtube.
 13. A method of insulating a wall according to claim 10, furthercomprising the step of replacing at least a portion of the restorablerefractory layer upon removal of the restorable layer due to the adverseconditions.
 14. A method of insulating a wall according to claim 13,wherein the step of replacing at least a portion of the restorablerefractory layer comprises reapplying the restorable refractory layerbefore the corrosive conditions affect the permanent refractory layer.15. A method of insulating a wall according to claim 13, furthercomprising the step of replacing the second stud connected to the firststud prior to replacing at least a portion of the restorable refractorylayer. 16-26. (canceled)